Flash tube holder assembly

ABSTRACT

A flash tube holder assembly includes a reflector for mounting two sets of spaced terminal blocks; one set mounts resilient contact strips to electrically engage and physically hold the terminal ends of a flash tube, while the other set mounts the ends of a trigger wire in longitudinally extending, contiguous relation to the tube. Each tube terminal block is formed of two sections interconnected by its resilient contact strip, which sections are manually separable to open the contact strips for tube removal.

United States Patent Hirschman et al.

[54] FLASH TUBE HOLDER ASSEMBLY [72] Inventors: Howard I. Hirschman; James C.

Evers, Maplewood, both of NJ.

[73] Assignee: Pitney Bowes-Sage, Inc., Hawthorne,

22 Filed: April 14,1971 21 Appl.No.: 134,006

[52] US. Cl. ..240/ll.4 R, 240/51.1l R, 313/234, 339/53, 339/256 T, 355/67 [51] Int. Cl. ..H0lr 33/08 [58] Field of Search ..240/] 1.4 R, 11.4 N, 20, 1.3, 240/51.11 R; 355/67; 339/53, 74 R, 74 L,

[151 3,692,994 [451 Sept. 19,1972

FOREIGN PATENTS OR APPLICATIONS 655,773 1963 Italy ..240/51.11R 1,091,494 10/1954 France ..240/51.l1R

Primary Examiner-Robert P. Greiner Att0meyWilliam D. Soltow, Jr., Albert W. Scribner, Martin D. Wittstein and Louis A. Tirelli 5 7] ABSTRACT A flash tube holder assembly includes a reflector for mounting two sets of spaced terminal blocks; one set mounts resilient contact strips to electrically engage and physically hold the terminal ends of a flash tube, while the other set mounts the ends of a trigger wire in longitudinally extending, contiguous relation to the 256 T; 313/49 324 tube. Each tube terminal block is formed of two sec- CM 3115. "iiiifls iil influfi liiillfi'filfi iifei ill UNITED STATES PATENTS contact strips for tube removal. 2,868,958 1/ 1959 Bounds ..240/ 1.3 11 Claims, 2 Drawing Figures 18 2 j 44 x44 |8b T 46 46 Pg: 80. 24 i K 38 58 I v -24 1 40 1e '2 lb 40 2o 14 f l 1 114 30 f 62 i 0 ,2 i '30 L7 74 q es- 7* 22 3e za/ 64 2211 2 721 PATENTEDsEP 19 I972 FIG. I

FIG.2

INVENTORS HOWARD I. HIRSCHMAN evens fl mih D m JAMES C.

ATTORNEY FLASH TUBE HOLDER ASSEMBLY BACKGROUND OF THE INVENTION The present invention relates to an assembly for physically holding a flash tube and, at the same time, providing for the electrical connection of the flashtube to external, flash initiating circuitry. In addition, the flash tube holder assembly of the invention mounts, separately from the flash tube, a triggering electrode in the form of a triggering wire for exciting the flash tube.

The apparatus of the invention has particular, but not necessarily limited application to electrophotographic systems which employ high intensity, short duration (flash) illumination of an original document to derive an optical image thereof for projection onto the electrostatically charged surface of an electrophotographic plate. Flash illumination has the advantage in such systems of accommodating high copy cycle rates. Since each copy cycle calls for the flashing of typically a plurality of flash tubes, in time the tubes burn out and must be replaced by service personnel.

It is accordingly an object of the present invention to provide a flash tube holder assembly of improved design which is capable of electrically engaging and holding the terminal ends of a gas discharge or flash tube in quick release fashion for convenient tube replacement. An additional basic object is'to provide a holder assembly of the above character which separately mounts a triggering electrode in longitudinally extending, capacitively coupled relation to the flash tube, such that removal of the flash tube does not disturb the triggering electrode.

Other objects of the invention will in part be obvious and in part appear hereinafter.

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a flash tube holder assembly which includes a first pair of spaced, insulative terminal blocks, each formed of two sections. A resilient contact strip, anchored at its ends to the sections of each terminal block, has a central portion conformed to electrically engage and hold each terminal end of a gas discharge (flash) tube. One section of each terminal block is secured to a reflector, while the other section is provided with a handle accommodating forceable distention of the contact strips to relax their hold on the tube terminal ends and thus facilitate tube replacement.

A second pair of spaced, insulative terminal blocks, supported by the reflector, mount the ends of a triggering electrode extending in contiguous relation to the flash tube; the triggering electrode adapted, when impressed with a suitable voltage, to ionize the gas within the tube and precipitate an electronic discharge. Since the triggering electrode is mounted separately from the flash tube, the latter may be replaced without disturbing the operative positioning of the triggering electrode.

The invention accordingly comprises the features of FIG. 1 is a side elevational view, partially broken away, of a flash tube holder assembly constructed according to a preferred embodiment of the invention; and

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1.

DETAILED DESCRIPTION Referring now to the drawing, the apparatus of the invention is shown holding a gas discharge tube, as generally indicated at 10. The tube is of conventional design having a glass envelope l2 filled with a suitable gas, such as xenon. Contact ferrules 14 are secured on the ends of the envelope. Anode and cathode electrodes 16 are mounted by and electrically connected to the contact ferrules 14 at each end of the flash tube 10.

A reflector 18 is provided with mounting tabs 18a by which the flash tube holder assembly is secured to a stationary frame, such as the chassis of an electrostatic photocopier. The reflector is broken away, as indicated at 18b, to illustrate that it may continue on to the left as seen in FIG. 1 to accommodate an additional flash tube or tubes.

Terminal blocks, generally indicated at 20, are provided at the ends of flash tube 10. As best seen in FIG. 2, each terminal block 20, a mirror image of the other, is formed of a suitable electrically insulating material, such as plastic, in two sections 22 and 24. Section 22 of each terminal block is secured to reflector 18 by a screw 26, preferably of plastic. The other section 24 is interconnected to section 22 by a resilient contact strip 30, but is not secured to the reflector. Referring to FIG. 2, section 22 of each terminal block 20 is formed with opposed recesses 32 interconnected by a rectangular passage 34. End 36 of contact strip 30 is provided with a raised tab 36a and is necked down to provide shoulders 36b (FIG. 1) which engage the end walls of recesses 32 at each end of the passage 34 through which the strip end extends so as to anchor it to terminal block section 22. Tab 36a may be provided by folding the end portion of contact end 36 back on itself. To assemble end 36 of contact strip 30 in section 22, it is inserted through the lower end of passage 34; tab 36a deflecting into the plane of the contact strip to accommodate insertion. When shoulders 36 b encounter the end wall of lower recess 32, tab 36a has cleared the upper end of passage 34, and it springs outwardly to anchor end 36 of contact strip 30 in terminal block section 22. The other end 38 of each contact strip 30 is anchored to terminal block section 24 by a screw 40.

The portion of each contact strip 30 intermediate terminal block section 22 and 24 is in the form of a clip 42, slightly greater than semicircular in cross-section and normally slightly less in diameter than contact ferrules 14. Thus the clips formed in contact strips 30 are adapted to firmly engage and make good electrical contact with the tube ferrules. Also, the width of the openings in clips 42 are less than the diameter of the contact ferrules so that tube 10 cannot slip out.

Still referring to FIG. 2, each terminal block section 24 is formed with a handle 44 which extends through an opening 46 in deflector 18. The free end of the handles is formed with a hole 44a in which the hooked end of a tool (not shown) may be inserted to pull terminal block section 24 in the direction indicated by arrow 48. This forcible separation of the terminal block sections causes contact strip 30 to distend, thereby increasing both the clip diameter and the width of clip opening to the point where tube can be readily removed and a replacement installed. A tongue 50 extending from terminal block section 24 slides in a groove 52 formed in terminal block 22 to guide the former in its movement relative to the latter.

in addition to mounting flash tube 10, the apparatus of the invention also mounts a triggering electrode 60, as best seen in FIG. 1. The triggering electrode is in the form of a wire extending in contiguous relation to the glass envelope 12 of the flash tube. The triggering wire 60 is physically mounted and electrically connected at its ends to separate L-shaped contact strips 62, such as by solder or welding. The contact strips are mounted by terminal blocks 64. Specifically, the lateral extending leg 62a of each contact strip 62 is inserted through a passage 63 in its respective terminal block 64, and a resilient tab 65 struck therefrom engages a shoulder provided by recessing the outer end of the passage to anchor the contact strips 62 in their terminal blocks in the same manner as the ends 36 of contact strips 30 are anchored in their terminal block sections 22. EAch terminal block 64 may be secured to reflector 18 by a screw or preferably integrally formed with one of the terminal block sections 22, which are secured to the reflector by screws 26.

The free ends of contact strips 30 and 62 extend beyond their mounting terminal blocks to receive electrical connectors, such as indicated in phantom at 70 in FIG. 2, for applying a high DC voltage across the tube and impressing a high pulsed AC voltage on triggering wire 60. The high voltage on the triggering wire, due to its proximate position to the tube, is capacitively coupled through the glass envelope to ionize the gas therein and thus precipitate an electron discharge between tube electrodes 16 resulting in the generation of a high intensity, short duration light output. When the flash tube needs to be replaced, the terminal block sections 22 and 24 are separated to distend contact strip 30 and free the ends of the tube. It will be noted that removal of the flash tube does not disturb the triggering wire which remains operatively positioned to fire a replacement flash tube. Thus, removal of the flash tube does not entail breaking the electrical connections or physical mountings for the triggering electrode.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

Having described the invention, what is claimed as new and desired to secure by Letters Patent is:

l. A flash tube holder assembly for mounting an elongated flash tube having a contact ferrule at each end, said assembly comprising, in combination:

A. a longitudinally elongated reflector;

B. a pair of longitudinally spaced, first terminal blocks, each formed in first and second sections, 1. said first section of each said first terminal block secured to said reflector;

C. a resilient contact strip mounted by each said first terminal block, each said strip having 1. its ends anchored to said first and second sections of each said first terminal blocks, and

2. a central portion arranged transversly of the flash tube and conformed to embrace the contact ferrule at one end of the flash tube; and

D. a handle secured to each said second terminal block section to facilitate forcible separation of said first and second terminal block sections along a direction transverse to the flash tube,

l. whereby to deform said central portions of said contact strips and thereby relax the physical hold on the contact ferrules of the flash tube.

2. The assembly defined in claim 1, which further includes A. a pair of spaced, second terminal blocks fixedly connected to said reflector; and

B. an elongated triggering electrode extending in contiguous, longitudinal relation to the tube, said triggering electrode mounted at its ends by said second terminal blocks.

3. The assembly defined in claim 2, wherein said second terminal blocks are respectively integrally formed with said first sections of said first terminal blocks.

4. The assembly defined in claim 2, wherein one of said first and second sections of each said first terminal block is formed with a passage therethrough, and the one end of each said contact strip anchored to each said one section is inserted through said passage, said one contact strip ends provided with means to engage said one terminal block section at opposed ends of said passages.

5. The assembly defined in claim 2, wherein said central portion of each said contact strip is in the form of a clip, slightly greaterthan semicircular in cross-section and slightly less in diameter than the contact ferrules of the flash tube, whereby to tightly embrace the contact ferrule and wherein forcible separation of said first and second terminal block sections opens said clips to release the flash tube.

6. A flash tube holder assembly for mounting an elongated flash tube, said assembly comprising, in combination:

A. a longitudinally elongated reflector;

B. a pair of longitudinally spaced, first terminal blocks carried by said reflector;

C. a pair of longitudinally spaced, second terminal blocks carried by said reflector;

D. a triggering wire mounted at its ends by said second terminal blocks and having an elongated, longitudinally extending central portion; and

E. separate contact means mounted by said first terminal blocks for electrically engaging and physically holding the contact terminal ends of the flash tube, whereby the flash tube is mounted independently of said triggering wire in contiguous, longitudinal relation with said central portion thereof.

7. The assembly of claim 6, wherein each said end of said triggering wire is mounted by a separate contact strip anchored to each said second terminal block.

8. The assembly of claim 7, wherein each said first terminal block consists of first and second sections, each said first section secured to said reflector, each said contact means in the form of a resilient contact strip anchored at its ends to said first and second sections and having a central portion conformed to electrically engage and physically hold a terminal end of the flash tube, each said second section including a handle for inducing forced separation of said sections and coincident distortion of said contact strip central portions to release the terminal ends of the flash tube.

9. The assembly defined in claim 8, wherein one end of each said triggering wire mounting contact strips and each said tube holder resilient contact strips is extended beyond their respective mounting terminal blocks to facilitate electrical connection to external circuitry.

10. The assembly defined in claim 8, wherein said central portion of each said resilient contact strip is in the form of a clip slightly in excess of semicircular in cross-section and slightly less in diameter than the terminal ends of the flash tube, whereby each said central portion tightly embraces one of the flash tube terminal ends.

11. The assembly defined in claim 8, wherein one of said first and second sections of each said first terminal block is formed with a tongue slidingly accommodated in a groove formed in the other of said first and second sections of each said first terminal block, whereby to guide said second sections in their movement relative to said first sections. 

1. A flash tube holder assembly for mounting an elongated flash tube having a contact ferrule at each end, said assembly comprising, in combination: A. a longitudinally elongated reflector; B. a pair of longitudinally spaced, first terminal blocks, each formed in first and second sections,
 1. said first section of each said first terminal block secured to said reflector; C. a resilient contact strip mounted by each said first terminal block, each said strip having
 1. its ends anchored to said first and second sections of each said first terminal blocks, and
 2. a central portion arranged transversly of the flash tube and conformed to embrace the contact ferrule at one end of the flash tube; and D. a handle secured to each said second terminal block section to facilitate forcible separation of said first and second terminal block sections along a direction transverse to the flash tube,
 1. whereby to deform said central portions of said contact strips and thereby relax the physicAl hold on the contact ferrules of the flash tube.
 2. a central portion arranged transversly of the flash tube and conformed to embrace the contact ferrule at one end of the flash tube; and D. a handle secured to each said second terminal block section to facilitate forcible separation of said first and second terminal block sections along a direction transverse to the flash tube,
 2. The assembly defined in claim 1, which further includes A. a pair of spaced, second terminal blocks fixedly connected to said reflector; and B. an elongated triggering electrode extending in contiguous, longitudinal relation to the tube, said triggering electrode mounted at its ends by said second terminal blocks.
 3. The assembly defined in claim 2, wherein said second terminal blocks are respectively integrally formed with said first sections of said first terminal blocks.
 4. The assembly defined in claim 2, wherein one of said first and second sections of each said first terminal block is formed with a passage therethrough, and the one end of each said contact strip anchored to each said one section is inserted through said passage, said one contact strip ends provided with means to engage said one terminal block section at opposed ends of said passages.
 5. The assembly defined in claim 2, wherein said central portion of each said contact strip is in the form of a clip, slightly greater than semicircular in cross-section and slightly less in diameter than the contact ferrules of the flash tube, whereby to tightly embrace the contact ferrule and wherein forcible separation of said first and second terminal block sections opens said clips to release the flash tube.
 6. A flash tube holder assembly for mounting an elongated flash tube, said assembly comprising, in combination: A. a longitudinally elongated reflector; B. a pair of longitudinally spaced, first terminal blocks carried by said reflector; C. a pair of longitudinally spaced, second terminal blocks carried by said reflector; D. a triggering wire mounted at its ends by said second terminal blocks and having an elongated, longitudinally extending central portion; and E. separate contact means mounted by said first terminal blocks for electrically engaging and physically holding the contact terminal ends of the flash tube, whereby the flash tube is mounted independently of said triggering wire in contiguous, longitudinal relation with said central portion thereof.
 7. The assembly of claim 6, wherein each said end of said triggering wire is mounted by a separate contact strip anchored to each said second terminal block.
 8. The assembly of claim 7, wherein each said first terminal block consists of first and second sections, each said first section secured to said reflector, each said contact means in the form of a resilient contact strip anchored at its ends to said first and second sections and having a central portion conformed to electrically engage and physically hold a terminal end of the flash tube, each said second section including a handle for inducing forced separation of said sections and coincident distortion of said contact strip central portions to release the terminal ends of the flash tube.
 9. The assembly defined in claim 8, wherein one end of each said triggering wire mounting contact strips and each said tube holder resilient contact strips is extended beyond their respective mounting terminal blocks to facilitate electrical connection to external circuitry.
 10. The assembly defined in claim 8, wherein said central portion of each said resilient contact strip is in the form of a clip slightly in excess of semicircular in cross-section and slightly less in diameter than the terminal ends of the flash tube, whereby each said central portion tightly embraces one of the flash tube terminal ends.
 11. The assembly defined in claim 8, wherein one of said first and second sections of each said first terminal block is formed with a tongue slidingly accommodated in a groove formed in the other of said first and second sections of each said first terminal block, whereby to guide said second sections in their movement relative to said first sections. 